Drying-kiln



UNITED STATES PATENT OFFIcE.

EDWARD HOLMES AND BRITAIN HOLMES, OF BUFFALO, NEW YORK.

' DRYING-KILN.

SPECIFICATION forming part of Letters Patent No. 231,168, dated August 17, 1880.

Application filed April 20, 1880 To all whom it may concern:

Be it known that we, EDWARD Romans and BRITAIN HOLMES, both citizens of the United States, residing in the city of Bufialo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Drying-Kilns, of which the following is a specification.

The object of the first part of our invention is to produce acontinuous rapid circulation of air through the material to be dried and through a thin condensing-space, as will be more clearly hereinafter shown, so as to effect a more thorough and rapid separation of the moisture therefrom, and to prevent the condensing of vapor and the consequent dripping of water within the kiln, which would be again converted into vapor by absorbing more heat therefrom; and it consists of a drying-kiln the sides of which are provided with an outer shell or wall, so as to leave a thin air-space between them, and having a suitable steam-heating device arranged horizontally at the bottom, in combination with a series of cold-water tubes arranged vertically within the said air-space outside of the kiln or drying-chamber, and adapted to any suitable water-forcing device for keeping upaconstant current or flow of cold water through the condenser, the inner wall or side of the kiln of said air-space having an opening below to allow the air, after its moisture has been condensed on the cold pipes within it, to pass again into the bottom of the kiln, where it is again heated and passes up through the lumber and kiln, and an opening at the top, through which theair passes, after being again charged with moisture, into the condensin g air-space, where itparts with its moisture and passes out, as before. The water on the condenser drips therefrom at the bottom of the air-space into a suitable receptacle, from which it is conducted away. The space in which the condenser is placed, being thin, but having a large area, confines the air within it very close to the cold condensing-tubes, so

, that it cannot radiate or expand outward from them, as it would if the condenser were placed in the kiln, thereby contracting the cold space without diminishing its area, and causing a more thorough and rapid condensation, as the warm moist air passes through it, than could (No model.)

be otherwise produced, and consequently an increased circulation, the said air-space being outside of the influence of the heat which rises from the kiln.

It is obvious that the colder the air is in the condensing-space the more rapid will be its descent through it, and that when warmed after it passes out it will again ascend through the lumber and kiln.

The second part of our invention relates to the heating apparatus; and it consists in a peculiar arrangement of the steam-coils at the bottom of the kiln, as will be more clearly hereinafter shown.

In the accompanying drawings, Figure l is a side elevation, showing a section through line X X, Fig. 3. Fig. 2 is a front view, showing the door closed; and Fig. 3 represents a top view of the kiln, showing the door opened. Fig. 4 is a vertical section through line Y Y, Fig. 1; and Fig. 5 is a horizontal section through line Z Z, Fig. 2, showing the arrangement of the steam-heating pipes and the track upon which the car for lumber or other mate rial to be dried is passed into the kiln, the cross-ties for holding and sfipportin g the track being left off, so as to show the heating device more clearly.

A A represent the two outer walls of the kiln; B B, the inner walls, which are placed sufficiently far apart to leave a thin air-space, 6, between them. Into this air-space, between the wallsA B, (see Figs. 1, 4E, and 5,) is placed a condensing apparatus, consisting of the large horizontal tubes 0 G and vertical tubes D. It is large enough to cover the whole side of the kiln, or nearly so, and a current of cold water is kept flowing through it in the direction of the arrows, so as to pass into the bottom tube, 0, and up through the vertical tubes D, into and out of the tube 0, as shown by the arrow in Fig. 1.

The condenser, it will be seen by reference to Fig. 1, covers nearly thewhole side of thekiln and is inclosed in a very thin space, 2', between the walls, as shown, for the purposes hereinbefore mentioned, the object being to secure as large a oondensingsurface as possible within a thin air-space. Any other well-known arrangement or device that would answer the purposes of a condenser and be adapted to receive a ourrent of cold water through it would be a suitable device when inclosed in a thin air-space, as mentioned.

Near the top of the kiln is fastened to the wall B a horizontal wall, B but this may not be always necessary, and can be dispensed with, if desired. At the bottom of the kiln is arranged the steam'heating device or apparatus, consisting of the bent tubes D l) and the S-shaped tubes E E, connected to the large tubes or manifolds F F. This arrangement of the tubes is well adapted for expansion and contraction, as all can expand or contract without interfering with each other and without warping or disturbing the plane of their horizontal arrangement. They are arranged in a plane which is inclined a little, so as to allow the condensed steam to drain or run off when necessary, the steam being admitted at the highest end.

G G represent the track,upon which alumber or other car is run into the kiln. It is sup ported upon the usual cross-ties, which, being well known, need not be described here. A perforated or open floor to allow the heat to pass up freely through it may or may not he used, as desired. For some purposes such a floor would not be necessary.

The wall B is provided with an opening, J, at the top and an opening, J, at the bottom, (see Figs. 1 and 4,) the wall being supported by suitable posts, 11, or other well-known means.

While the lumber or other material is being dried the heated airand vapors pass up through the lumber or other material from the heating apparatus, and up through the kiln II. in the direction of the arrows, (see Fig. 4,) through the opening J, into the passage 2', which being much colder than the kiln H, and consequently heavier, it causes the air and moisture to descend and depositthe condensed vapor on the condenser, from which it drips at the bottom into the trough H, and passes out into any suitable receptacle. The cold air, now deprived of a large portion, if not all, of its moisture, passes through the opening J to the heating apparatus, where it is again heated, as before, and passes up, thereby producing a constant and rapid circulation, as the air and vapor passes over a large condensing-surface in aclose or thin air-space, so that it cools more quickly than it would in a larger space, as hereinbefore mentioned, and consequently produces a more rapid circulation.

If the condenser were placed in the kiln it is obvious that a large portion of the moist air would not reach it or have much, if any, circulati0n,or be condensed; whereas if the moist air is passed through an extended but thin space, so as to be forced to pass close to the condensing apparatus during its passage downward, a much larger proportion of it, if not all, would be condensed in less time, thereby increasing the rapidity of the circulation and the capacity of the kiln for drying wet or damp material.

We make no claim in this application to the improved door illustrated in the drawings, but reserve the right to make a separate application for Letters Patent therefor.

We claim as our invention-- 1. A drying-kiln provided with a suitable heating apparatus arranged in the lower part of the kiln, in combination with aseries ofcondensing-tubes adapted to a suitable waterforcing device, for the purposes specified, and arranged in a large but thin air-space, as and for the purposes described.

2. A dryingkiln having a series of bent tubes, I) D and S'shaped tubes E E, connected to the manifolds, whereby the required temperature is imparted to the kiln, substantially as and for the purposes described.

EDWARD HOLMES. BRITAIN HOLMES. Witnesses JAMEs SANGSTER, M. l). FIELD. 

